Access floor systems are widely used in modem office buildings. These floors are also referred to as elevated floors or computer floors. Access floor systems were initially used in computer rooms for cooling applications because computers generate a great deal of heat and to accommodate the extensive electrical wiring requirements. Today, access floors are also widely used in commercial office construction. Access floor systems provide a space between the access floor and a base floor to accommodate the electrical and mechanical systems, building controls, communication wiring and other components required for operating the building. Access floor panels are removable which allows easy access to the wiring, components and electrical outlets.
The flooring of access floor systems is provided by a plurality of square floor panels. Access floor systems include a plurality of pedestals that support the square shaped floor panels. The pedestals of access floor systems in the past supported a plurality of metal stringers that formed a frame for supporting the perimeter of each of the square floor panels. U.S. Pat. No. 3,396,501 provides an example of such a stringer-based system. Stringer based systems are disadvantageous however because they are expensive and the stringer frame imposes a permanently installed structure that makes access to components and services under the floor more difficult. Stringer less systems have been developed wherein the pedestals directly support the corners of the square floor panels. Canadian Patent No. 946,578 provides an example of such a system. This patent describes an access floor system that can be structured as either a stringer type assembly or a stringer less type assembly.
The floor panels of these systems may leave a gap around the perimeter of the floor panels that permits a flow of air through the access floor. In buildings with under floor air this may be disadvantageous as this airflow loss makes it difficult and or inefficient to maintain air pressure under the access floor. This is a significant drawback because a specified air pressure is required beneath the access floor for ventilation purposes in order to deliver air from beneath the access floor to the space above the floor in a consistent and controlled manner. However, air cannot be delivered in an efficient way through diffusers in the floor panels in an access floor if there is a high level of leakage in through the floor panel edges.
There is therefore a need for a modular stringer less access floor system wherein the floor panels are sealed effectively to provide an air pressure beneath the access floor that permits air to be delivered to a space from beneath the floor in a controlled and efficient manner.